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G4LivermoreNuclearGammaConversionModel Class Reference
#include <G4LivermoreNuclearGammaConversionModel.hh>
Inheritance diagram for G4LivermoreNuclearGammaConversionModel:
Protected Member Functions | |
| G4double | GetMeanFreePath (const G4Track &aTrack, G4double previousStepSize, G4ForceCondition *condition) |
| Protected Member Functions inherited from G4VEmModel | |
| G4ParticleChangeForLoss * | GetParticleChangeForLoss () |
| G4ParticleChangeForGamma * | GetParticleChangeForGamma () |
| virtual G4double | MaxSecondaryEnergy (const G4ParticleDefinition *, G4double kineticEnergy) |
| const G4MaterialCutsCouple * | CurrentCouple () const |
| void | SetCurrentElement (const G4Element *) |
Protected Attributes | |
| G4ParticleChangeForGamma * | fParticleChange |
| Protected Attributes inherited from G4VEmModel | |
| G4VParticleChange * | pParticleChange |
| G4PhysicsTable * | xSectionTable |
| const std::vector< G4double > * | theDensityFactor |
| const std::vector< G4int > * | theDensityIdx |
Detailed Description
Definition at line 43 of file G4LivermoreNuclearGammaConversionModel.hh.
Constructor & Destructor Documentation
◆ G4LivermoreNuclearGammaConversionModel()
| G4LivermoreNuclearGammaConversionModel::G4LivermoreNuclearGammaConversionModel | ( | const G4ParticleDefinition * | p = 0, |
| const G4String & | nam = "LivermoreNuclearGammaConversion" |
||
| ) |
Definition at line 41 of file G4LivermoreNuclearGammaConversionModel.cc.
44 isInitialised(false),
45 crossSectionHandler(0),meanFreePathTable(0)
46{
47 lowEnergyLimit = 2.0*electron_mass_c2;
48 highEnergyLimit = 100 * GeV;
49 SetHighEnergyLimit(highEnergyLimit);
50
51 verboseLevel= 0;
52 // Verbosity scale:
53 // 0 = nothing
54 // 1 = warning for energy non-conservation
55 // 2 = details of energy budget
56 // 3 = calculation of cross sections, file openings, sampling of atoms
57 // 4 = entering in methods
58
59 if(verboseLevel > 0) {
61 << "Energy range: "
62 << lowEnergyLimit / MeV << " MeV - "
63 << highEnergyLimit / GeV << " GeV"
64 << G4endl;
65 }
66}
G4DLLIMPORT std::ostream G4cout
G4ParticleChangeForGamma * fParticleChange
Definition: G4LivermoreNuclearGammaConversionModel.hh:71
Definition: G4VEmModel.hh:102
◆ ~G4LivermoreNuclearGammaConversionModel()
|
virtual |
Definition at line 70 of file G4LivermoreNuclearGammaConversionModel.cc.
71{
72 if (crossSectionHandler) delete crossSectionHandler;
73}
Member Function Documentation
◆ ComputeCrossSectionPerAtom()
|
virtual |
Reimplemented from G4VEmModel.
Definition at line 121 of file G4LivermoreNuclearGammaConversionModel.cc.
125{
126 if (verboseLevel > 3) {
128 << G4endl;
129 }
130 if (GammaEnergy < lowEnergyLimit || GammaEnergy > highEnergyLimit) return 0;
131
133 return cs;
134}
G4double FindValue(G4int Z, G4double e) const
Definition: G4VCrossSectionHandler.cc:379
◆ GetMeanFreePath()
|
protected |
◆ Initialise()
|
virtual |
Implements G4VEmModel.
Definition at line 78 of file G4LivermoreNuclearGammaConversionModel.cc.
80{
81 if (verboseLevel > 3)
83
84 if (crossSectionHandler)
85 {
86 crossSectionHandler->Clear();
87 delete crossSectionHandler;
88 }
89
90 // Read data tables for all materials
91
93 crossSectionHandler->Initialise(0,lowEnergyLimit,100.*GeV,400);
94 G4String crossSectionFile = "pairdata/pp-pair-cs-"; // here only pair in nuclear field cs should be used
95 crossSectionHandler->LoadData(crossSectionFile);
96
97 //
98
99 if (verboseLevel > 0) {
103 }
104
105 if (verboseLevel > 0) {
107 << "Energy range: "
110 << G4endl;
111 }
112
113 if(isInitialised) return;
115 isInitialised = true;
116}
Definition: G4CrossSectionHandler.hh:57
Definition: G4String.hh:105
void LoadData(const G4String &dataFile)
Definition: G4VCrossSectionHandler.cc:187
void Initialise(G4VDataSetAlgorithm *interpolation=0, G4double minE=250 *CLHEP::eV, G4double maxE=100 *CLHEP::GeV, G4int numberOfBins=200, G4double unitE=CLHEP::MeV, G4double unitData=CLHEP::barn, G4int minZ=1, G4int maxZ=99)
Definition: G4VCrossSectionHandler.cc:140
G4ParticleChangeForGamma * GetParticleChangeForGamma()
Definition: G4VEmModel.cc:109
◆ SampleSecondaries()
|
virtual |
Implements G4VEmModel.
Definition at line 138 of file G4LivermoreNuclearGammaConversionModel.cc.
143{
144
145// The energies of the e+ e- secondaries are sampled using the Bethe - Heitler
146// cross sections with Coulomb correction. A modified version of the random
147// number techniques of Butcher & Messel is used (Nuc Phys 20(1960),15).
148
149// Note 1 : Effects due to the breakdown of the Born approximation at low
150// energy are ignored.
151// Note 2 : The differential cross section implicitly takes account of
152// pair creation in both nuclear and atomic electron fields. However triplet
153// prodution is not generated.
154
155 if (verboseLevel > 3)
157
160
161 G4double epsilon ;
162 G4double epsilon0Local = electron_mass_c2 / photonEnergy ;
163
164 // Do it fast if photon energy < 2. MeV
165 if (photonEnergy < smallEnergy )
166 {
167 epsilon = epsilon0Local + (0.5 - epsilon0Local) * G4UniformRand();
168 }
169 else
170 {
171 // Select randomly one element in the current material
172 //const G4Element* element = crossSectionHandler->SelectRandomElement(couple,photonEnergy);
175
176 if (element == 0)
177 {
179 << G4endl;
180 return;
181 }
183 if (ionisation == 0)
184 {
186 << G4endl;
187 return;
188 }
189
190 // Extract Coulomb factor for this Element
193
194 // Limits of the screening variable
196 G4double screenMax = std::exp ((42.24 - fZ)/8.368) - 0.952 ;
197 G4double screenMin = std::min(4.*screenFactor,screenMax) ;
198
199 // Limits of the energy sampling
200 G4double epsilon1 = 0.5 - 0.5 * std::sqrt(1. - screenMin / screenMax) ;
201 G4double epsilonMin = std::max(epsilon0Local,epsilon1);
202 G4double epsilonRange = 0.5 - epsilonMin ;
203
204 // Sample the energy rate of the created electron (or positron)
205 G4double screen;
206 G4double gReject ;
207
208 G4double f10 = ScreenFunction1(screenMin) - fZ;
209 G4double f20 = ScreenFunction2(screenMin) - fZ;
210 G4double normF1 = std::max(f10 * epsilonRange * epsilonRange,0.);
211 G4double normF2 = std::max(1.5 * f20,0.);
212
213 do {
215 {
216 epsilon = 0.5 - epsilonRange * std::pow(G4UniformRand(), 0.3333) ;
217 screen = screenFactor / (epsilon * (1. - epsilon));
218 gReject = (ScreenFunction1(screen) - fZ) / f10 ;
219 }
220 else
221 {
222 epsilon = epsilonMin + epsilonRange * G4UniformRand();
223 screen = screenFactor / (epsilon * (1 - epsilon));
224 gReject = (ScreenFunction2(screen) - fZ) / f20 ;
225 }
227
228 } // End of epsilon sampling
229
230 // Fix charges randomly
231
232 G4double electronTotEnergy;
233 G4double positronTotEnergy;
234
236 {
237 electronTotEnergy = (1. - epsilon) * photonEnergy;
238 positronTotEnergy = epsilon * photonEnergy;
239 }
240 else
241 {
242 positronTotEnergy = (1. - epsilon) * photonEnergy;
243 electronTotEnergy = epsilon * photonEnergy;
244 }
245
246 // Scattered electron (positron) angles. ( Z - axis along the parent photon)
247 // Universal distribution suggested by L. Urban (Geant3 manual (1993) Phys211),
248 // derived from Tsai distribution (Rev. Mod. Phys. 49, 421 (1977)
249
250 G4double u;
252 G4double a2 = 3. * a1;
253 // G4double d = 27. ;
254
255 // if (9. / (9. + d) > G4UniformRand())
257 {
259 }
260 else
261 {
263 }
264
265 G4double thetaEle = u*electron_mass_c2/electronTotEnergy;
266 G4double thetaPos = u*electron_mass_c2/positronTotEnergy;
268
269 G4double dxEle= std::sin(thetaEle)*std::cos(phi),dyEle= std::sin(thetaEle)*std::sin(phi),dzEle=std::cos(thetaEle);
270 G4double dxPos=-std::sin(thetaPos)*std::cos(phi),dyPos=-std::sin(thetaPos)*std::sin(phi),dzPos=std::cos(thetaPos);
271
272
273 // Kinematics of the created pair:
274 // the electron and positron are assumed to have a symetric angular
275 // distribution with respect to the Z axis along the parent photon
276
277 G4double electronKineEnergy = std::max(0.,electronTotEnergy - electron_mass_c2) ;
278
279 // SI - The range test has been removed wrt original G4LowEnergyGammaconversion class
280
281 G4ThreeVector electronDirection (dxEle, dyEle, dzEle);
282 electronDirection.rotateUz(photonDirection);
283
285 electronDirection,
286 electronKineEnergy);
287
288 // The e+ is always created (even with kinetic energy = 0) for further annihilation
289 G4double positronKineEnergy = std::max(0.,positronTotEnergy - electron_mass_c2) ;
290
291 // SI - The range test has been removed wrt original G4LowEnergyGammaconversion class
292
293 G4ThreeVector positronDirection (dxPos, dyPos, dzPos);
294 positronDirection.rotateUz(photonDirection);
295
296 // Create G4DynamicParticle object for the particle2
298 positronDirection, positronKineEnergy);
299 // Fill output vector
300
301 fvect->push_back(particle1);
302 fvect->push_back(particle2);
303
304 // kill incident photon
307
308}
Definition: ThreeVector.h:41
Definition: G4DynamicParticle.hh:74
const G4ThreeVector & GetMomentumDirection() const
G4ParticleDefinition * GetDefinition() const
G4double GetKineticEnergy() const
Definition: G4Element.hh:98
Definition: G4IonisParamElm.hh:52
void SetProposedKineticEnergy(G4double proposedKinEnergy)
Definition: G4ParticleChangeForGamma.hh:129
Definition: G4ParticleDefinition.hh:68
const G4Element * SelectRandomAtom(const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
Definition: G4VEmModel.hh:459
void ProposeTrackStatus(G4TrackStatus status)
Member Data Documentation
◆ fParticleChange
|
protected |
Definition at line 71 of file G4LivermoreNuclearGammaConversionModel.hh.
Referenced by Initialise(), and SampleSecondaries().
The documentation for this class was generated from the following files:
